Unit 46 Quiz

Question 1

What is used to provide supplemental heat for a heat-pump window unit?

Answer 1

Electric resistive heater strips

Question 2

Single room air conditioning units generally range in capacity from ______ btu/h.

Answer 2

4000 to 24,000

Question 3

The evaporator typically operates _______ the dew point temperature of the room air.

Answer 3

Below

Question 4

Compressors used in window air conditioners are typically hermetically sealed and either _____ or _______.

Answer 4

Reciprocating or rotary

Question 5

True or false: all 208V/230V power cords have the same plug configuration.

Answer 5

False

Question 6

True or false: In the heat-pump heating cycle, the refrigerant condenses in the indoor coil.

Answer 6

True

Question 7

True or false: The capacity of a heat-pump is less in colder weather so supplemental heat will probably be provided.

Answer 7

True

Question 8

True or false: The heat-pump systems use a three-way reversing valve and check valves to ensure correct flow through the correct metering device at the proper time.

Answer 8

False

Question 9

True or false: The most common refrigerant used in older window air conditioners is R-12

Answer 9

False

Question 10

True or false: New models of window air conditioners use R-410A refrigerant.

Answer 10

True

Question 11

Coil temperature for a window air conditioner should be no lower than _______ F.

Answer 11

35 degrees F

Question 12

How is the condensate from the evaporator disposed of from a window unit?

Answer 12

Drained out of the pan or evaporation using a slinger ring

Question 13

When doing a bench test to check a window unit to see if it has a proper charge, what is the purpose of blocking the condenser air flow?

Answer 13

Because the condenser and evaporator will be operating in the same ambient temperature, blocking the airflow over the condenser will increase head pressure and push the refrigerant out of the condenser.

Question 14

The round piece fastened to the outer tips of the condenser fan blade is called the ______.

Answer 14

Slinger ring

Question 15

The window unit must be installed in such a manner that air can circulate across the _______ and not recirculate or high head pressures will result.

Answer 15

Condenser

Question 16

What happens if a window air conditioner is installed with an inward pitch?

Answer 16

Condensate could leak into the room

Question 17

What is the result of a dirty air filter on a window unit?

Answer 17

Dirty coils
low suction pressure
potential ice blockage in the evaporator

Question 18

Window installation of room units are either double-hung or ______ windows.

Answer 18

Casement

Question 19

What is the purpose of the energy saver switch on some window units?

Answer 19

To allow or deny the fan motor from cycling on/off with the compressor

Question 20

When bench checking a window unit for a low charge, where should the sweat line be to indicate a full charge?

Answer 20

All the way to the compressor

Question 21

The correct head pressure for a window unit that uses R-410A is ______ psig.

Answer 21

420

Question 22

What is performed on a window unit for basic preventive maintenance?

Answer 22

• Cleaning the filters and coils
• lubricating the motor if needed
• clean out condensate drain pan
• clean blower fan blades
• check for mold on the foam insulation
• check capacitor

Question 23

How can you identify if a window unit is a through-the-wall type unit?

Answer 23

The sides will not have vents/louvers.

Question 24

What type of fan motor is used in a window unit?

Answer 24

PSC or Shaded pole

Question 25

Dimming of lights and television picture rolling over when the AC unit starts is a sign of what?

Answer 25

There are other loads on the AC circuit

Question 26

Your manifold gauge is attached as last resort to confirm a low charge. What are some indications that the window unit has a low charge?

Answer 26

- Evaporator not sweating from bottom to top, - suction line not sweating almost all the way to the compressor, - compressor not drawing FLA.

Question 27

Any air gaps between the window unit and window should be filled with _____ to keep hot air from entering and conditioned air from escaping.

Answer 27

Foam strip or insulation

Question 28

Voltmeter probes placed on the thermostat terminals will have a meter reading of ______ if the thermostat switch is open.

Answer 28

Line voltage

Question 29

A large window air conditioner can be used to cool several rooms. How is that accomplished?

Answer 29

Use a floor fan to circulate air to the other rooms.

Question 30

What are two types of window unit chassis?

Answer 30

Wrap-around or slide out/sleeve

Question 31

A window unit that operates on 115V uses ______ the current than a window unit that operates on 208V/230V.

Answer 31

Twice

Question 32

The rear of a window unit , if not properly supported, could cause what type of problems?

Answer 32

Condensate/drain problems, vibration noise

Question 33

Two types of fan blades are used in a window unit, what are they?

Answer 33

Squirrel cage and propeller blades

Question 34

How is fresh air introduced into a room and indoor air exhausted through a window unit?

Answer 34

A Damper that’s operated from the front unit

Question 35

Can a thermostatic valve or automatic expansion valve be used to replace a restricted capillary tube metering device in a window unit?

Answer 35

Yes